How I got jQuery Quicksand working with WordPress?

Not sure it is entirely your problem, but you have a syntax error here:

<script src="https://wordpress.stackexchange.com/questions/32648/<?php bloginfo("template_directory'); ?>js/jquery.easing.js"></script>

…you need to add the trailing slash to bloginfo('template_directory'), like so:

<script src="https://wordpress.stackexchange.com/questions/32648/<?php bloginfo("template_directory'); ?>/js/jquery.easing.js"></script>

EDIT

Looking at your browser source, your loop markup is working properly, but your quicksand script link doesn’t appear to be output anywhere. Where and how are you calling it?

EDIT 2

Okay, the quicksand script is loading now; however, it appears to be using a jQuery no-conflict mode format that will cause it to execute immediately, rather than on document.ready. You might try changing this format:

(function($) {
    // quicksand script
})(jQuery);

…to this:

jQuery(document).ready(function($) {
    // quicksand script
});

Also: you’re loading a TON of scripts. I would make sure that you have them cascaded properly, so that dependent scripts load after their dependencies.

Note: using wp_enqueue_script(), which includes a $deps argument, is especially helpful here, and is the best-practice implementation for enqueueing scripts.